A temperature-insensitive fiber-optic refractive-index sensor based on optically heated long-period grating (LPG) is presented. The LPG is manufactured in a short section of cobalt-doped optical fiber (COF), which can be thermally stabilized through a pump light. Two fiber Bragg gratings (FBGs) are manufactured in COF and single-mode fiber (SMF), respectively, to monitor the local sensor and surrounding medium temperature. Experimental results demonstrate that this fiber-grating-based miniature refractive-index sensor can efficiently eliminate temperature cross-sensitivity in the temperature range of 5 ∼ 60°C.
- fiber-optic sensor
- long-period grating (LPG)
- Optical heating
- refractive-index sensor
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering